The present invention relates to a method of decaffeinating liquid medium without substantial removal of desirable components contained in such medium.
In the past, there have been many methods of decaffeinating liquid medium. Decaffeination is most commonly used to remove caffeine from coffee beans, although decaffeination processes are used to remove the caffeine in teas; in chocolate or cocoa, which are derived from the cocoa bean. Typically, there are three methods of removing caffeine from a liquid medium, which include the following: decaffeination utilizing organic solvents, the Swiss extraction method, and decaffeination by utilization of a super critical extraction.
The method of decaffeinating using organic solvents, such as ethyl acetate or methylene chloride, involves mixing the organic solvent with hydrated beans or with a water extract made from hydrated beans. The caffeine is then recovered from the organic solvent. However, there are several disadvantages involved with this method. Organic solvents are very expensive and there is an inherent risk in handling large quantities of organic solvents. Additionally, consumers have a negative connotation of organic solvents being in contact with a food item. There is also the problem of removal of the organic solvents to meet the United States Federal Drug Administration regulations.
The Swiss extraction method was developed to avoid the use of organic solvents for decaffeination of coffee. It is an indirect method of removing caffeine which involves passing a water extract through a carbon bed. A carbon bed removes desirable aroma and flavor compounds as well as the caffeine. Because carbon is very abrasive and dirty to handle, the carbon bed itself is a disadvantage. Due to the abrasiveness of the carbon, equipment must be repaired and replaced frequently. Carbon does not allow for economical recovery of the caffeine.
Decaffeination by utilization of super critical extraction involves very expensive instrumentation that operates at 2,000 to 6,000 psi. The cost has been a major deterrent in the United States. The major problem with this method other than cost is that operations at such a high pressure can be a safety hazard. Additionally, the process involves high pressures so that down time due to mechanical failure has also been a problem.
In addition to the methods of decaffeination described above, there has also been an attempt to reduce caffeine by the employment of many different types of adsorbents and ion exchange resins. However, these methods still have not solved the problems of desirable flavor and aroma being removed in addition to the caffeine. In addition, the prior methods can have detrimental affects on acidity of the green bean extract. Thus, it is highly desirable to have a method of removing caffeine that is not cost prohibitive, is not abrasive on equipment, and does not remove the aroma and flavorings which consumers desire.